Applied Mechanics and Materials Vols. 353-356

Abstract: A design method of reliability-based structural optimization has a powerful advantage because some random variables can be considered. However, the sensitivity analysis of reliability with respect to random variables is very complicated and its computational cost is very expensive. Thus, in this paper, based on hybrid high dimensional model representation (HDMR) and first order second moment (FOSM) method, a new method for the reliability-based structural optimization is proposed. A numerical example is presented to demonstrate the computational efficiency of the proposed method. It is shown that the proposed method can reduce the number of finite element calculation and has the high efficiency.

Abstract: A new soil-rock mechanics method—parallel cellular element method is introduced. In this method the integer analysis of structure is changed into a series of part analysis by using the idea of Cellular Automata. It may have a good future in soil-rock mechanics. The basic principle is introduced; the computing steps and results are presented. Based on the numerical results, the feasibility, advantages of cellular element method are discussed.

Abstract: Change the general idea of the moment distribution method to analyze problems,not repeat fixed and relax joints to achieve a balance moment, but by the correction of the bending stiffness,deduced the moment carryover factor,moment once distributed and transferred twice you can get the moment exact solution.. Particularly suitable for the calculation of continuous beam internal forces and determination of envelope diagram and the influence lines of beam.

Abstract: Relying on a practical application in pre-stressed concrete box-girder with corrugated steel web, four models of Twin-PBL shear connector are made and experimented in push-out test. The main research contents are influences for bearing capacity and load-slip relationship. The results show that: when the size of holes on the steel plate has a definite value, the connectors bearing capacity get a significantly development when the diameter of reinforced-throughout increases in the appropriate range. If the space between reinforced-throughout and holes are too small, the coarse aggregate will be prevented into the holes so as to reduce its bearing capacity. In addition, thickness of steel plate has less influence on bearing capacity of connectors. All models show similar load-slip trend and superior ductility. Finally, according to comparing and analyzing differences between calculated values from recommended formulas and measured values from tests, a new formula is deduced which can estimate the test results well. The standardization of push-out test needs further research so that Twin-PBL Shear Connectors can be widely used in project.

Abstract: Beam bridge is forced to vibrate when moving loads pass, which will bring up potential damage to the safety of people and bridge. Tuned Mass damper (TMD) is introduced to study the vibration of beam bridge. A mid-span deflection model of beam bridge is established when moving loads pass with a constant velocity successively. The numerical results shows that TMD can reduce the amplitude of midspan efficiently when long-time moving loads pass through beam bridge.

Abstract: Based on the analogy between equations of gas seepage in coal seam and that of thermal conduction, a simulative method on gas seepage in coal seam was proposed through that thermal conduction interpreted as gas seepage. The laws of gas emission from borehole in homogeneous and heterogeneous coal seam were analyzed using this method. It indicates that the simulative results of the gas emission from borehole in homogeneous coal seam were satisfied with the corresponding theoretical results during the early stage of gas seepage, while a tolerance between the numerical results and the theoretical ones was appeared in the later period. This is due to the simplification as solving the theoretical equations. The results of heterogeneous coal seam show that curves of gas emission rate conform to the actual situation. The numerical simulation method on the law of gas emission from borehole in coal seam is feasible.

Abstract: In this paper, a class of elliptic equation with convex-concave nonlinear term is considered. By the variational methods, we give a sufficient condition which insures that the problem considered in the present paper has at a nontrivial nonnegative solution.

Abstract: Due to the incorporation of enrichment functions in the displacement approximation, the mesh in the extended finite element method (XFEM) can be independent of the internal discontinuities. In the present paper, crack-void interaction problems in viscoelastic materials are investigated with the XFEM. The effect of the distance between crack and void on crack opening displacement is mainly studied in time domain.

Abstract: To study the flow pattern in the process of oil-water stirring in three paddle stirring tank, RNG k-ε turbulent model and VOF model are adopted to simulate the flow field at different time in the stirred tank with the baffle. The results showed that, in the stirring process, inverted cone manifold was formed in the center of the stirring shaft. The stratified area was formed in the baffle and gradually transported to the bottom of the tank. The two circular flows were formed among three groups of blades. And the axially acting of the fluid was strong, which made homogeneous stirring in the stirred tank. At the same time the radial flow of the cross-section inside the tank increased because of the baffle.

Abstract: Pseudo-spectral domain decomposition method (PS-DDM) is proposed for the dynamic elastoplastic torsion problem. Numerical examples illustrate the effectiveness of this method.